115 research outputs found
Magnetization Measurements on Single Crystals of Superconducting Ba0.6K0.4BiO3
Extensive measurements of the magnetization of superconducting single crystal
samples of Ba0.6K0.4BiO3} have been made using SQUID and cantilever force
magnetometry at temperatures ranging between 1.3 and 350 K and in magnetic
fields from near zero to 27 T. Hysteresis curves of magnetization versus field
allow a determination of the thermodynamic critical field, the reversibility
field, and the upper critical field as a function of temperature. The lower
critical field is measured seperately and the Ginzburg-Landau parameter is
found to be temperature dependent. All critical fields have higher T = 0 limits
than have been previously noted and none of the temperature dependence of the
critical fields follow the expected power laws leading to possible alternate
interpretation of the thermodynamic nature of the superconducting transition.Comment: 33 pages, 11 figures, accepted for publication in Philosophical
Magazine B on 7 August 1999. This paper supplies the experimental details for
the argument presented in our PRL 82 (1999) p. 4532-4535 (also at
cond-mat/9904288
Space construction system analysis. Part 2: Platform definition
The top level system requirements are summarized and the accompanying conceptual design for an engineering and technology verification platform (ETVP) system is presented. An encompassing statement of the system objectives which drive the system requirements is presented and the major mission and subsystem requirements are described with emphasis on the advanced communications technology mission payload. The platform design is defined and used as a reference configuration for an end to space construction analyses. The preferred construction methods and processes, the important interactions between the platform design and the construction system design and operation, and the technology development efforts required to support the design and space construction of the ETVP are outlined
Anomalous Superconducting Properties and Field Induced Magnetism in CeCoIn5
In the heavy fermion superconductor CeCoIn5 (Tc=2.3K) the critical field is
large, anisotropic and displays hysteresis. The magnitude of the critical-field
anisotropy in the a-c plane can be as large as 70 kOe and depends on
orientation. Critical field measurements in the (110) plane suggest 2D
superconductivity, whereas conventional effective mass anisotropy is observed
in the (100) plane. Two distinct field-induced magnetic phases are observed: Ha
appears deep in the superconducting phase, while Hb intersects Hc2 at T=1.4 K
and extends well above Tc. These observations suggest the possible realization
of a direct transition from ferromagnetism to Fulde-Ferrel-Larkin-Ovchinnikov
superconductivity in CeCoIn5.Comment: 4 pages, 3 figure
Spin-Peierls transition in NaV2O5 in high magnetic fields
We investigate the magnetic field dependence of the spin-Peierls transition
in NaVO in the field range 16T-30T. The transition temperature exhibits
a very weak variation with the field, suggesting a novel mechanism for the
formation of the spin-Peierls state. We argue that a charge ordering transition
accompanied by singlet formation is consistent with our observations.Comment: 4 pages, 3 figures, final version to appear in Phys. Rev. B (RC
Barriers to participation in mental health research: are there specific gender, ethnicity and age related barriers?
<p>Abstract</p> <p>Background</p> <p>It is well established that the incidence, prevalence and presentation of mental disorders differ by gender, ethnicity and age, and there is evidence that there is also differential representation in mental health research by these characteristics. The aim of this paper is to a) review the current literature on the nature of barriers to participation in mental health research, with particular reference to gender, age and ethnicity; b) review the evidence on the effectiveness of strategies used to overcome these barriers.</p> <p>Method</p> <p>Studies published up to December 2008 were identified using MEDLINE, PsycINFO and EMBASE using relevant mesh headings and keywords.</p> <p>Results</p> <p>Forty-nine papers were identified. There was evidence of a wide range of barriers including transportation difficulties, distrust and suspicion of researchers, and the stigma attached to mental illness. Strategies to overcome these barriers included the use of bilingual staff, assistance with travel, avoiding the use of stigmatising language in marketing material and a focus on education about the disorder under investigation. There were very few evaluations of such strategies, but there was evidence that ethnically matching recruiters to potential participants did not improve recruitment rates. Educational strategies were helpful and increased recruitment.</p> <p>Conclusion</p> <p>Mental health researchers should consider including caregivers in recruitment procedures where possible, provide clear descriptions of study aims and describe the representativeness of their sample when reporting study results. Studies that systematically investigate strategies to overcome barriers to recruitment are needed.</p
Participative Leadership and Organizational Identification in SMEs in the MENA Region: Testing the Roles of CSR Perceptions and Pride in Membership
The aim of this research is to explore the process linking participative leadership to organizational identification. The study examines the relationship between participative leadership and internal CSR perceptions of employees and also investigates the role that pride in membership plays in the affiliation of CSR perceptions with organizational identification. By studying these relationships, the paper aspires to contemplate new presumed mediators in the association of participative leadership with organizational identification as well as determine a possible novel antecedent of employee CSR perceptions. Empirical evidence is provided from data that was collected through a survey distributed to employees working for small- and medium-sized enterprises in three countries in the Middle East and North Africa regions, particularly the United Arab Emirates, Lebanon, and Tunisia. Findings show that participative leadership leads to positive internal CSR perceptions of employees and that these CSR perceptions lead to pride in membership which, in turn, results in organizational identification. Implications of these findings are also discussed
Exploring Elementary Students\u27 Environmental Attitudes and Commitment Towards the Environment: Grandpa, Don\u27t Put That Down the Storm Drain!
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